I have a situation where a user will be entering data into column A in either HEX or DEC format. In column B, I am converting all entries to DEC.

I want to be able to prevent a duplicate entry in column A, based on the result of the DEC conversion in column B.

I have used this code in Validation before to deal with similar issues -

=COUNTIF($A$1:A1,A1)=1

This would work great if every entry was the same format, but in my situation, there could be two rows that have the "same" value, but one in HEX and one in DEC.

If there is another solution unrelated to COUNTIF, I am open to any idea.



Thanks in advance for any assistance.